As a technique of this kind, for example, the technique described in Japanese Patent No. 3767874 (PATENT LITERATURE 1) is known. This technique concerns a hydraulic excavator with a work attachment connected to an upperstructure, characterized by including a work attachment posture detecting means, work attachment operating means, calculating means to receive a posture detection signal from the work attachment posture detecting means and an operation signal from the work attachment operating means, and control means to control the moving speed of the work attachment according to an output signal from the calculating means, in which the calculating means sends the output signal to make the moving speed of the work attachment corresponding to the operation signal lower when the posture detection signal indicates a larger distance between a given position of the work attachment and the upperstructure.